The gorilla toolkit's APIs are inadequate and it seemed like quite a few people agreed too because most of them said they rolled their own solutions to do things that certain gorilla libs did but with a more intuitive and friendly API.
Go really isn't that young either. It's been what at least 4 years now? There's no excuse. It's not like the language is 6 months old.
As for re-inventing stuff, it's more so go's ecosystem rather than revel's shortcomings although revel does have its own shortcomings if you were to compare it to something like rails and not express.
Revel seems to be somewhere in between rails and express in terms of opinions which is fine but if it's going to make me less productive then I'm simply not going to use it.